Main Entry:

tau

Pronunciation:

\ˈtau̇, ˈtȯ\

Function:

noun

Etymology:

Middle English taw, from Latin tau, from Greek, of Semitic origin; akin to Hebrew tāw taw

Date:

14th century

1 : the 19th letter of the Greek alphabet — see alphabet table 2 : a short-lived elementary particle of the lepton family that exists in positive and negative charge states and has a mass about 3500 times greater than an electron —called also tau particle 3 : a protein that binds to and regulates the assembly and stability of neuronal microtubules and that is found in an abnormal form as the major component of neurofibrillary tangles